Depending on the form of tennis being played the length of the match will vary. Standard tennis is played to best of five sets for the men and best of three sets for the women.
To win a set a player must win six games and also win by two games. Winning a game is a case of reaching 40 points and then winning the next point, the score goes 15, 30, 40 then the game point. If both players reach 40 then the next point will be advantage, this means that if the player on advantage wins the next point then they have won the game, however if the other player gets the point then the score drops back to 40-40 also known as deuce.
A tie break is played to decide a set that is drawn 6-6. In a tie break situation the first player to score seven points win, they must also be won by two points. This means that a tie break can go on as long as needed with the score just going up as long as the teams keep drawing level. Once one team goes two points in front after the six point mark then the winner is awarded the set.